The story:
I have a 1994 Accord CD-5 EX (f22b1 engine) which as of the last month or so has been getting progressively worse. The care would be misfiring maybe once a month, then once a week, and now pretty much every drive. It will happen at two times, either the car is accelerating and at 2k revs in 2nd or 3rd gears, or when idle and drops to 500 revs (less likely to happen when just starting up - happens when stopped at a red light). When it happens either I seem to lose all power (no matter how far I press the pedal), or I lose some power and I can compensate by accelerating more. Also some of the time it will buck and shake, other times it will not (when stopped at a light it will more than likely be bucking).

What I have done:
Now I have not had any check engine lights come on before, I have replaced the ignition coil, spark plugs (I will be replacing the distributor cap and rotor, maybe wires as well), the Australian version does not have an EGR to check, there doesn't seem to be any vacuum leaks.

It really is intermittent, it will not 100% of the time happen and even when it does it varies, then returns to normal about 1-2 seconds later. Any ideas on what else I can check?

 

Maybe unbolt the G101 ground. It is on the driver's side of the upper intake manifold. Clean the bolt and eyelet with wire brush or sand paper. Then reattach. See pic below for location.

Next, remove the 7.5 amp backup/radio in the engine bay fuse box for a minute to reset the ECU. Drive the car until the problem occurs again, then check for codes. If the car is an automatic, then check for TCU codes as well.

The common diy thread on top of the gen tech help forum has a link to checking engine codes. It also had a link for online shop manuals where you can download the 94 shop manual for free as a pdf.

 

Finally a day that isn't raining!
Reset the ECU, drove after (misfired a couple times on the drive) and no CEL came on. Tried to check for codes anyway but nothing came up (same for TCU as well).

 

What is the code set?

 

@RobinsonRicer If by "code set" you mean the codes that came up... as I mentioned - there was none. If you mean something else, please explain what it is.

 

oh, nope I misunderstood and then was thrown off by pahondas comment.

So:
Fuel pressure check- rent or buy the kit with the banjo bolt
Vacuum gauge test- cheap vacuum gauge will tell a lot
Electrical system test- get a multimeter and check the ignition coil, take a look at your spark plugs for an indication of an issue.

Is it misfiring or stuttering?

 

As I mentioned in the original post, it varies. Some of the time the car will shudder, some of the time it will not. Sometimes I lose all power (even if I floor it) some of the time it is simply reduced (and I can still accelerate through it).

It has a new ignition coil and about a month or two old spark plugs (I will look at them again and see if I can find anything of notice), when I get time and money I will try a fuel pressure check and vacuum gauge.


Note: Something new has come up that it was not doing before, it has been able to downshift (driving an automatic) while the problem is occuring (so the revs will go up to say 3000 rather than the problem range of 1800-2000) and continue to occur until the time has finished (always around 1-3 seconds). Also early on I attempted to put it into neutral while the problem was happening to see if it would continue to occur, but it did not (while in neutral), as soon as I shifted back into gear it came up again.

 

Im not too good with automatics but it seems to be there may be a transmission problem then. Perhaps youre low on transmission fluid.

 

It's not transmission fluid, or lack of any other fluids (I top them up regularly). I don't think there is a transmission problem as it is not changing gears (or trying to) when the issue occurs.

 

Block-off plate where the EGR valve would bolt to?